دورية أكاديمية
Distinct regulatory effects of the Na,K-ATPase gamma subunit.
| العنوان: | Distinct regulatory effects of the Na,K-ATPase gamma subunit. |
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| المؤلفون: | Pu HX; Department of Medicine, McGill University, Montreal, Quebec H3G 1Y6, Canada., Scanzano R, Blostein R |
| المصدر: | The Journal of biological chemistry [J Biol Chem] 2002 Jun 07; Vol. 277 (23), pp. 20270-6. Date of Electronic Publication: 2002 Apr 19. |
| نوع المنشور: | Journal Article; Research Support, Non-U.S. Gov't |
| اللغة: | English |
| بيانات الدورية: | Publisher: Elsevier Inc. on behalf of American Society for Biochemistry and Molecular Biology Country of Publication: United States NLM ID: 2985121R Publication Model: Print-Electronic Cited Medium: Print ISSN: 0021-9258 (Print) Linking ISSN: 00219258 NLM ISO Abbreviation: J Biol Chem Subsets: MEDLINE |
| أسماء مطبوعة: | Publication: 2021- : [New York, NY] : Elsevier Inc. on behalf of American Society for Biochemistry and Molecular Biology Original Publication: Baltimore, MD : American Society for Biochemistry and Molecular Biology |
| مواضيع طبية MeSH: | Sodium-Potassium-Exchanging ATPase/*metabolism, Amino Acid Sequence ; Animals ; HeLa Cells ; Humans ; Molecular Sequence Data ; Mutagenesis ; Protein Transport ; Rats ; Sodium-Potassium-Exchanging ATPase/chemistry ; Sodium-Potassium-Exchanging ATPase/genetics |
| مستخلص: | The two variants of the gamma subunit of the rat renal sodium pump, gamma(a) and gamma(b), have similar effects on the Na,K-ATPase. Both increase the affinity for ATP due to a shift in the enzyme's E(1) <--> E(2) conformational equilibrium toward E(1). In addition, both increase K(+) antagonism of cytoplasmic Na(+) activation. To gain insight into the structural basis for these distinct effects, extramembranous N-terminal and C-terminal mutants of gamma were expressed in rat alpha1-transfected HeLa cells. At the N terminus, the variant-distinct region was deleted (gammaNDelta7) or replaced by alanine residues (gammaN7A). At the C terminus, four (gamma(a)CDelta4) or ten (gamma(a)CDelta10) residues were deleted. None of these mutations abrogates the K(+)/Na(+) antagonism as evidenced in a similar increase in K'(Na) seen at high (100 mm) K(+) concentration. In contrast, the C-terminal as well as N-terminal deletions (gammaNDelta7, gamma(a)CDelta4, and gamma(a)CDelta10) abolished the decrease in K'(ATP) seen with wild-type gamma(a) or gamma(b). It is concluded that different regions of the gamma chain mediate the distinct functional effects of gamma, and the effects can be long-range. In the transmembrane region, the impact of G41R replacement was analyzed since this mutation is associated with autosomal dominant renal Mg(2+)-wasting in man (Meij, I. C., Koenderink, J. B., van Bokhoven, H., Assink, K. F. H., Groenestege, W. T., de Pont, J. J. H. H. M., Bindels, R. J. M., Monnens, L. A. H., Van den Heuvel, L. P. W. J., and Knoers, N. V. A. M. (2000) Nat. Genet. 26, 265-266). The results show that Gly-41 --> Arg prevents trafficking of gamma but not alphabeta pumps to the cell surface and abrogates functional effects of gamma on alphabeta pumps. These findings underscore a potentially important role of gamma in affecting solute transport, in this instance Mg(2+) reabsorption, consequent to its primary effect on the sodium pump. |
| المشرفين على المادة: | EC 7.2.2.13 (Sodium-Potassium-Exchanging ATPase) |
| تواريخ الأحداث: | Date Created: 20020404 Date Completed: 20020712 Latest Revision: 20210209 |
| رمز التحديث: | 20221213 |
| DOI: | 10.1074/jbc.M201009200 |
| PMID: | 11929868 |
| قاعدة البيانات: | MEDLINE |
| تدمد: | 0021-9258 |
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| DOI: | 10.1074/jbc.M201009200 |